Osmos

This post is from the now defunct website “A GameDev Plays…”, copied here for posterity

Ever wondered how things would be if you were just a single cell, living
a simple cell life? Floating around, absorbing your smaller neighbours,
desperately avoiding being absorbed by your larger neighbours? Well
wonder no more, as that is exactly the theme behind
Osmos, a vaguely physics based puzzler,
that aims to be relaxing, but often ends up exceedingly frustrating.

In Osmos, you play as the aforementioned cell. Movement is created by
ejecting part of yourself and as a result moving in the opposite
direction due to conservation of
momentum.
Understanding momentum is absolutely vital in this game, as your cell
shrinks (due to ejected mass for movement) or slows, it becomes more
mobile and vice versa. Ejecting material is just a matter of clicking on
your cell where you want it to emerge. Clicking repeatedly results in
more material being ejected and thus a greater change in velocity. That,
plus keys to zoom in/out and speed-up/slow-down time is all that is
required to control the game - simple and well-designed.

The challenge in most levels is to grow. Each level contains various
other cells and there is a simple rule for how interaction occurs. If
you touch another cell and you are larger, then the other cell is slowly
absorbed, its mass becoming part of yours. If you are smaller, then you
are absorbed. If your cell is totally absorbed then the game is over -
time to restart. A nice touch in Osmos is the use of colour. If another
cell is bigger than yours it is coloured red, if it is smaller then it
is blue. So the general rule is: move towards blue and avoid red. The
player quickly knows exactly how to succeed, but of course the challenge
lies in actually managing to succeed.

This game is definitely challenging - verging on frustrating. Osmos may
be easy to understand and may have the style of a relaxing game, but
many of the levels can be frantic at the start as the player desperately
tries to get big quickly. If the player has not reached a good size
after the first few seconds, it is usually best just to restart. On the
Steam version there are 42 levels across 3 groupings and the feel
between them is completely different. There are: ambient levels which
are the closest to puzzles; force attractor levels, where everything
rotates around a central object; and artificial life levels where you
are up against AI opponents. Interestingly there are more levels and
groupings available on the mobile version of the game (which I have not
played). I guess that is the better selling platform. The levels are
randomly generated, and the RNG gods can easily condemn you to a quick
death. However, the player can retry the same level configuration or
generate a new one on demand.

While this is a pretty, enjoyable and well designed game, the change in
style can be jarring. The game suggests it is all about a calm casual
experience. The music, graphics, speed and even the marketing copy all
promote relaxing gameplay. After the initial scramble for size, the game
often slows down to a survival of the fattest. Here the game provides
the promised tranquillity, as your cell slowly bounces around (even with
sped up time) and the music plays. Although until that point, Osmos is
anything but relaxing. It is unlikely to be an attempt at modelling
cellular life, so instead it feels a strange juxtaposition. Considering
the sharp drop off in players reaching certain Steam achievements many
people find the game too hard (or perhaps they don’t appreciate the
style change) - 68% of players complete the first 5 levels; only 14%
complete the following 10. Potential purchasers should be aware of what
they are getting - a good physics puzzler which can sometimes be frantic
and sometime slow - often in the same level.

Osmos is on Steam and from its website for PC, Mac and Linux for US$9.99
(Steam page or
Website). It has been bundled.